@fen: pink;
@tianlan: skyblue;
@zuo: left;
@you: right;
@kuan: width;
@gao: height;
@bgc: background-color;
@bai: white;

.common() {
    font: 50px;
    color: aquamarine;
}


.head {
    display: flex;
    height: 800px;
    width: 800px;
    justify-content: space-between;
    .common;

    .@{zuo} {
        @{bgc}: @tianlan;
        @{gao}: 400px;
        @{kuan}: 400px;
        .common;
    }

    .@{you} {
        @{bgc}: @fen;
        @{gao}: 400px;
        @{kuan}: 400px;
        .common;
    }

}

.son(@baise) {
    @{bgc}: @baise;
}

.son2(@lvse:@lv){
    @{bgc}:@lvse;
}


@lv:green;
.body {
    .good {
        .son(@bai);
    }
    
    .goods2{
        .son2();
    }   
}